Elderly male smokers with right lung tumors are viable candidates for KRAS mutation screening

Genetic aberrations in tumor driver genes provide specific molecular targets for therapeutic intervention, which can greatly improve therapeutic outcomes. Here, we analyzed the mutational frequency of EGFR and KRAS gene, as well as EML4-ALK rearrangement, and summarized the clinicopathological characters of Chinese lung cancer patients. We detected the mutation spectrum of 1033 primary lung cancer patients. The analyzed clinicopathological parameters included gender, age at diagnosis, smoking status, pathological TNM stage, tumor morphology and location, visceral pleural invasion, and histological type. A total of 618 patients had mutations in EGFR or KRAS gene as well as rearrangement of EML4-ALK. Exon 19 deletions and L858R in the EGFR gene were the most frequent mutations. Left-side lung cancer was more common in female patients carrying the KRAS mutation. Rearrangement of EML4-ALK was more common in non-tobacco-using male patients, who also exhibited a higher likelihood of visceral pleura invasion. Elderly females who never smoked and possessed 1-20 mm stage I adenocarcinomas in the right side exhibited a higher frequency of EGFR mutations. Elderly male smokers with right lung tumors were viable candidates for KRAS mutation screening.